# 1.2 Points, Line Segments, Lines and Rays…OH MY!

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1.2 Points, Line Segments, Lines and Rays…OH MY!

Mental Math Solve these subtraction problems. Write your answer on your slate. 9 – 0 = 12 – 6 = 16 – 9 = 17 – 8 = 90 – 40 = 140 – 70 =

Math Message Read SRB pages 88 and 89.
In your Math Notebook, please list three places where geometry can be found in our world. Be ready to share.

Reviewing Points, Line Segments, Lines and Rays
When you connect two points using a straightedge, you create a line segment A B points

Points, Endpoints and Line Segments
B line segment letters are often used to name a line segment ONE name for this line segment is “line segment AB” A short way to write “line segment AB” is AB Another name for this line segment is “line segment BA” What is the short way to write “line segment BA?”

Stop and Chat! endpoint endpoint A B How would you describe a line segment to someone who has never seen one before? What are some examples of line segments that we can find in the world? EXAMPLE: part of a spider web

Lines point point A B lines extending line segment AB in both directions and drawing an arrowhead at each end makes a LINE This line is called “line AB” or “line BA” A short way to write the names of these lines is AB or BA

Stop and Chat! A B How is a line different from a line segment?
point point A B How is a line different from a line segment? What are some examples of lines that we can find in the world? EXAMPLE: The horizon in a landscape

Short way to write the name is CD
Ray endpoint point C D rays line segment that goes on without end in only ONE direction Point C is the ENDPOINT of the ray CD The letter that names the ENDPOINT is ALWAYS written first. Short way to write the name is CD

What are some examples of lines that we can find in the world?
Stop, Try and Chat! endpoint point C D Short way to write the name is CD On your slate, draw ray ZY. Remember that the endpoint of the ray is ALWAYS written first. What are some examples of lines that we can find in the world? Example: Hitting a golf ball

Let’s Review! Is it ever possible to draw all of a line?
All of a line segment? All of a ray? How many line segments can you name using the points marked on this line? How many rays can you name?

Independent work MJ page 4

Wrap it UP! In your Math Notebook… Draw and label YX Draw and label HG
Draw and label VB